Clem wrote:Hm. My brand new Patrol that is now only just run gets steering wobble on what seems to be a perfectly smooth freeway. Not constantly but on and off and sufficient that the passengers notice. Even driving dead straight. First question: Is this normal? I assume not. Second question: Do I tell the local dealer to fix it or not? It is after all a warranty issue.

I think it is unlikely that you have a problem. I get the same symptoms on the R21 in some stretches and on other stretches the ride is smooth.

On the other hand, it only takes a very small problem to generate these results in a Patrol, and many cars seem to have it. Some cars seem to be more problematic than others. I had a problem for a while, but it was due to very badly worn ball joints on the drag link. Since that was replaced, it's been fine.

However, I very much doubt your local Nissan agent has anybody with sufficient knowledge and experience to stand any real chance of finding the problem, and while I agree that it should be sorted under warranty, but in reality I think it will just be an exercise in frustration.

Firstly, before you even take it to Nissan, have a wheel alignment check done and take carefull note of the values. Maximize the toe in and see if that helps.

If you want to, you can take it in and ask them to do th following:
1) Jack it up, remove the front wheels and all the steering linkages, then check the kingpin bearing preload (there are specifications in the manual for the amount of force that should be necessary to turn the hub assemblies). Also, check that the suspension bushes are all in good condition and properly torqued, particulalrly the panhard rod.
2) Before re-fitting the drag link and track rod, feel that the ball joints are all tight and smooth. Thre must be absolutely no detectable play in any of these.
3) If the problem has not been identified by this stage, the steering box should be removed from the vehicle and the adjustment checked. Once again there are torques in the manual, but this cannot be done on the vehicle. When re-fitting, they need obviously to re-fill and bleed the power steering.
4) Check the wheel bearing play, or just re-torquee the wheel bearings. If they have the right tools, this step will take them half an hour, if they don't, don't let them touch it... They need a special spanner and probably three different torque wrenches (196Nm, 5-7Nm and around 80Nm if I remember correctly)
5) Check that there is no runout on the drive flanges, and that the wheels are true.

I will actually be very surprised if they have the tool to do all the above correctly and as per specifications, but if they don't, they may well make the problem worse.

If all the above fails to produce results, try rotating the tires, and then just live with it...

Clem wrote:Hm. My brand new Patrol that is now only just run gets steering wobble on what seems to be a perfectly smooth freeway. Not constantly but on and off and sufficient that the passengers notice. Even driving dead straight. First question: Is this normal? I assume not. Second question: Do I tell the local dealer to fix it or not? It is after all a warranty issue.

I think it is unlikely that you have a problem. I get the same symptoms on the R21 in some stretches and on other stretches the ride is smooth.

On the other hand, it only takes a very small problem to generate these results in a Patrol, and many cars seem to have it. Some cars seem to be more problematic than others. I had a problem for a while, but it was due to very badly worn ball joints on the drag link. Since that was replaced, it's been fine.

However, I very much doubt your local Nissan agent has anybody with sufficient knowledge and experience to stand any real chance of finding the problem, and while I agree that it should be sorted under warranty, but in reality I think it will just be an exercise in frustration.

Firstly, before you even take it to Nissan, have a wheel alignment check done and take carefull note of the values. Maximize the toe in and see if that helps.

If you want to, you can take it in and ask them to do th following:
1) Jack it up, remove the front wheels and all the steering linkages, then check the kingpin bearing preload (there are specifications in the manual for the amount of force that should be necessary to turn the hub assemblies). Also, check that the suspension bushes are all in good condition and properly torqued, particulalrly the panhard rod.
2) Before re-fitting the drag link and track rod, feel that the ball joints are all tight and smooth. Thre must be absolutely no detectable play in any of these.
3) If the problem has not been identified by this stage, the steering box should be removed from the vehicle and the adjustment checked. Once again there are torques in the manual, but this cannot be done on the vehicle. When re-fitting, they need obviously to re-fill and bleed the power steering.
4) Check the wheel bearing play, or just re-torquee the wheel bearings. If they have the right tools, this step will take them half an hour, if they don't, don't let them touch it... They need a special spanner and probably three different torque wrenches (196Nm, 5-7Nm and around 80Nm if I remember correctly)
5) Check that there is no runout on the drive flanges, and that the wheels are true.

I will actually be very surprised if they have the tool to do all the above correctly and as per specifications, but if they don't, they may well make the problem worse.

If all the above fails to produce results, try rotating the tires, and then just live with it...

Peter, thank you so much for once again sharing your technical insights. I am traveling outside SA at the moment but am going to re-read and follow your advice carefully on my return. Re the pre-load, do you have a number and can it be checked with a simple spring balance?

Note that this measurement is to be made without the grease seal on the back and with the side shaft removed, so it's a bigger job than I thought!

Peter, thank you very much again. At least it's some sort of a parameter to start with. If I don't have at least 1.75kg with the seal and side shaft in place I will be wondering about it all. I'll also take comparative measures of the two swivels. If they are wildly different, may indicate something.

If anyone on this list happens to at some be working on a GX front axle that is good, would appreciate it if you could measure your preload with the grease seal and side shaft installed.